Aeration unit and support therefor



P. F. MORGAN t AERATION UNIT AND SUPPORT THEREFOR Filed Aug. ,17, 1945 Patented Sept. 5, 1950 UNITED] Application August 17, 1945, serial Ne. 610,934 v l2 claims. ((31.261-124),k

A complete diffuser unit of the above.V type generally comprises a hollow anchoring structure or stanchion to which may be pivotally mounted the diffuser unit proper. The diffuser unit proper may beas disclosed in Patent 2,328,655 to Lan-y nert. Thus it may consist of two or more pipe lengths jointedly connected to jack-knife in the upwposition of the unit. In the down position of the unit, which is the normal operating position, the pipe lengths are generally extended and, attheend of the pipe system, there is a diffuser assembly. Each such assemblyhas one or more manifolds from which extend diffuser elements generally transversely therefrom, the diffuser elements being as long and as numerous as condip tions require.

yWhile the entire pipe system and manifolds are customarily made 4of mechanically, strong material, such as iron vor steel, the air' diffuser elements themselves are generally made of ceramic or similar material having substantially less mechanical strength than iron or steel. -As is well known, such diffuser elements are generally provided with a large number of minute apertures through which air or other aeriform body is diffused into the liquid mass of sewage or other material being treated.

In the normal operation of an air diffuser system, particularly one used for treating sewage, the creation of well-dened sewage currents within the tank is desirable. As a rule, substantial turbulence is created'and the. sewage flow occurs at a substantialy rate. Because of the existence of such turbulent conditions, it is found that considerable stresses are created overthe entire diffusery unit. l

ItA isclear from the general construction of a diifuser unit that the center of gravity of the entire system undernormal operation is quite low. The greater the number of diffuser elements carried by the manifold, the lower is the center of gravity of the entire diffuser unit.

A diffuser unit having a lowcenter of gravity and extending into a turbulent liquid will have substantial stresses andrstrains on the various portions of the unit. .The elasticity lof the vmetal pipes l.supporting themanifold and `diffuserele- 'STATES PATENT- v Philip F. MQrgamfEImhurSt, Ill., VassgnorI toKChif I cago Pump Company, a corporation ufl-Delaments, together with the relatively largeI exposed surface of the manifolds and diffuser elements, results in movement of. the entire diffuserf unit.

Such movementgenerates strainsy at the various4 joints of the entire diffuser system. vIn the prior art, the joint atthe stanchion carrying theentire articulated diffuser unit has had great strains created therein.

erally` results in constant action at the joints,

particularly at the stanchion joint, andk in the and maintenance of well-defined liquidcurrents. in the sewagetank and maydeleteriously affect.`

sewage treatment. l

and stresses is the breakage ofwdiffuser elements. In an attempt to -avoid the above, undesirable characteristics, it has beenthe, general practice to have a comparatively small number of 'diffuser elements for. each diifuser assembly to. minimize the effects of the reactive and. turbulent forcesv existing around the diffuser. assembly. And the stiffness .ofrthedepending pipes hasbeen .relied upon to maintainthe diffuserelements more or less rigidly in position.

It is clear that the cost of an installation for 'zsewage, treatment involves` as an importantele--. ment the number of difuser,units. Byfvirtue of.i the invention herein, it is possible` to/provide.

fewer but larger diffuser units. Theinvention herein provides means for stabilizing a diffuser,A

unit against whipping or strain incident to normal diffusion operation. The -invention in .gene f eral provides means for suppressing movement of manifolds duringr the normal operation of a diuser assemly, thereby.almostfcompletely eliminating whipping This permitsthe use of.4 large diffuser assemblies and also provides ygreatlonger has any primary mechanical -functionsof supporting and stiffening the diffuser assembly.

It is thus possible to design thesupply pipe'with scant regard for the stresses that would normally have tobe considered.. I l l I Referring to the drawings:

Figure 1 is a sectional elevation of an aeration tank ,system embodying the inventiong-Eigllre 2 The low. center ofgravity of the. entire diffuser unit and .the existence of subl stantial. forces at the bottomzend.thereoffgene'.

A further undesirable-result of whipping is a vertical transverse section of the system of Figure 1, taken along the line 2-2 of Figure 1. Figure 3 is a plan view of a, supporting element for the manifold. Figurel 4 is a front elevation of the supporting element, and Figure 5 is a ver.- tical section taken therethrough.

In the drawings, Vtankzlll of 'concrete or other suitable ymaterial has bottom "Il', end walls I2 and I3 and side walls I4 and I5. One of the walls, here shown as side wall I4, has an overhanging ledge I6 in the general form of a half Y. Top portion I1 of wall I4 is channeled at I8, this being an influent sewage channel 4having fend Y ports I9 and 20 giving access to thetank proper. Channel I8 is covered with plate 2l to form a catwalk along the tank. Disposed within the l tank is shown an articulated air diffusing unit generally indicated by numeral 25. This unit, except for the length of: header and number of diffuser elements, is generally described in the above patent toIiannert.

lDiffuser unit 25 includes hollow stanchion 26 suitably anchored' fin the top of over-hanging ledge I6. This stanchion may be supplied with compressed air from pipe 28 extending along the L,

upper portion -of channel I8. Pivotalrly secured to stanchion 26 on a pivot pin 21, is fitting 29 in the general form of an elbow. This elbow is hol low and communicates with the interior of stanchion l26. Elbow 29 has a tapped end into which pipe 33 may be threaded. Pipe -l may be .of any suitable material such as iron or steel and, at the end, is threaded into pivot joint 3l. Both elbow fitting 29v and pivot joint 3l are so disposed that pivotal movement in vertical planes normal to g;

tank wall I4 is provided. Joint 3l may have the relatively -movable Vportions `provided with bosses and a stop bolt to limit .joint movement, as in the. Lannert patent.

lPivot joint 3l carries pipe section 32 provided with-fitting 33 at the end thereof. Fitting 33 may resemble the conventional T tting and carries manifolds 34 and 35 at opposite sides thereof. As

is clearly evident from Figure 2., manifolds 34' parallel Ato the tankbottom. One series 31 of diffuser v'elements may vextend towardr tank wall I4,'whi1e the remaining series 38 may extend awayfrom tank wall I4. y

`In ord'erto 'anchor the diffuser assembly unde normal 'operating conditions, supporting standards are provided at spaced intervals. Standards 40, '4I 'and 42 may be disposed, respectively, l

at fitting 33' and near 'the ends of manifolds 34 and 35. Additional 'standards may be provided, as desired;

Iasiiu'ch-as the'selst'andards all have the same construction, only one will be described in vdetail. `lE'ach standard comprises fa vertical holelow pedestal 45 Jhaving `a flaring `base 46 'boltedior permanently anchored to the tank bottom. Fede estal AI5-'may be of any "suitable material, preferably iron or steel, and has a cylindrical top 41 threaded on the lnSiClethereef.A

Threaded m1301101@ f4?! 'or the pedestal is pest 50 tofwliicnfinayibeboltedleap 5l. Vfoi-tp' fet-can f several advantages.

ries saddle 52 rigidly mounted thereon, this being in the form of an upwardly extending block having a V-shaped cut-out 53 formed therein. Cut-out 53 is suiciently large so that tting 33 or manifolds 34 and 35 can comfortably and snugly rest therein. As is clearly evident from Figures 1 and l2, the saddles are alinedso that the V notches extend along a line parallel to the tank side I4. Bolt 56 may be provided to maintain a. standard in predetermined adjusted position. The supporting height for the standard may lbe determined by rotating post 50 with respect to pedestal 45.

It is preferred to adjust the effective supporting height of the standards so that top pipe section 30 will be inclined from the vertical. This angular disposition of the two pipes results in Thus, pipe 3U is supported between elbow 29 and joint 3|. This is desir'- able since no great dead weight is impressed on 'elbow 29. In addition, pipes Se and 32 are system. This is particularly desirable in that no great stresses are impressed upon pivot joint 3l. While temporary strains may be impressed upon this pivot joint during raising or lowering ofthe entire unit, such strains are quick-lyre` lieved. on the `pivot joints have tended to damage them.-

A further desirable advantage of `the relaxed condition of the pivot joint `is that there is n'o opportunity for grit to work into the machinedjoint surfaces and gradually destroy themv One or more stops -51 may be carried by'frtting 33 and 'manifolds 34 andf35 to prevent the 'dif'- fuser elements from striking Wall I4. Stop V51, as is evident from Figure 1f, 'extends from 'tti'ng 33 vor the manifolds, as the case may be, beyond diff-user elements 36 toward wall I4 in the nor-- mal operating position. pipe or s'olid rod and is preferably provided with an upwardly curved tip 58.

The entire diffuser unit may be raised out fromfor lowered into the tank by exerting suitable force upon elbow 29, as by a cable engaging the creo-k of the elbow. It is preferred to have pipe 32 somewhat shorter than pipe 3i) so that, nwhen the unit is raised 'above the tank, the diffuser assembly will clear the top of thel tank. This is clearly shown in Figure l of the Lannert patent previously mentioned. In lowering the unit `into the tank, the diffuser assemblywill tend -tosw-ing toward wall I4. This is evident from the propor tions, vmounting and disposition of thecomponent parts 'of each diffuser unit. `It is preferred to proportion sto-p 51 so that, when the entire unit is short of its -nal operating position, it will' just barely touch the wal-l and permit the bottom of tting 33 and manifolds 3'4" and 35 to engage V-slot 53 of each standard at the side nearest wall I4. Thereafter, slot 53 takes 'over the f guiding action ofthe manifold assembly and moves the manifold and diffuser elements away f from wall I4. Thus, stop 51 will clear wall I4 and permit the diffuser assembly to loe-cradled 'in the standards in the operating position of the diffuser unit.

It is evident from the above that manifolds 34 and 35 may be as long as desired and may have Vas vmany diffuser Yelements extending therefrom as may be deemed necessary. If desired, auxil- In the absence of the standards, strains This stop may bev of k iary means acting on the manifolds may be provided for aiding in raising or lowering the same so that pipes 30 and 32 will not bear the` entire weight of manifolds and diffuser elements during such operations; A substantial portion of the weight of the entire diffuser unit maybe neutralized `by keeping air at a low pressure in l the unit during the raising or lowering. Thus,

by having just enough air pressure to prevent any liquid from entering any part of the diffuser unit, but no-t enough to create any substantial turbulence, it is possi-ble to take advantage .Cil

of the buoyancy of the contained air in supporting the vweight of the manifolds and diifuser elements during the raising or lowering thereof.y

While the diffuser unit has been described with particular reference to its use in a sewage treating tank, it is not limited to such use, 'for it may be used in tanks for aerating or gasifying any desired liquid. In the latter use rany suitable gasor gasiform may be usedin lieu of air. Because of the supporting means of the present invention, the diffuser assembly may be made larger than heretofore, thereby making commercially feasible the use of air diifusion units in long channels, such as in the channel between the primary settling tank and the aeration tank in a sewage treating system.

' I- claim:

l. In an aeration tylpe of sewage treating apparatus, va sewage tank having a side wall and bottom wall, the sidewall of said tank having a top portion over-hanging said tank, a support .anchored in said over-hanging portion of said Wall, angair pipe section pivotally mounted on said support for movement `in a vertical plane generally normal to said wall, means for supplying said pipe section with compressed air, a second -pipe section jointedly carried by the free end of said first pipe section and in communication therewith, said second pipe section being normally pivotal-ly movable in a vertical plane generally parallel to the planek of movement of said rst pipe section, an air diffuser assembly l carried by the free end of said second lpipe section, said assembly including at :least one header Aand a plurality of diffuser elements extending from said header, said diffuser elements being supplied with air through said headerand said pipe sections for diffusion into said liquid sewage, a stop carried by said assembly, said pipe sections `being adapted to be raised and folded in jack-knife fashion for raising and lowering said diffuser assembly, said stop extending toward the nearest tank wall beyond any portion of the diffuser assembly in normal operating position, means on said tank botto-m for supporting said pipe sections and-said diffuser assembly in xed position during normal vdiffusion operation,

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PA'rEN'rsI Number Name Date 2,144,385 Nordell Jan. 17, 1939 2,221,346 Durdin, Jr. NOV. 12, 1940 2,328,655 Lannert Sept. 7, 1943 

